xmlto is a shell-script tool for converting XML files to various
formats.
At the moment it supports conversion from docbook, xhtml1 and fo format
to various output formats (awt, fo, htmlhelp, javahelp, mif, pdf, svg,
xhtml, dvi, html, html-nochunks, man , pcl, ps, txt, xhtml-nochunks,
epub).

Note that this package does not enforce too many dependencies so
depending on what you want to convert to, you may need to manually
install other packages (e.g. epub requires to install "zip").
